Yamaha adds EFI on 2005 50-90 4-Strokes

S

Sea Wolf

New member
In my search for a new engine for my C-Dory Cruiser, I've found that for 2005 Yamaha has added Multi-Port Electronic Fuel Injection to it's 50, 60, 75, and 90 HP mid-range four-stroke outboards.

So now we have another alternative to the Suzukis, also offering EFI in the mid-range 4-strokes.

They've also raised the compression on the larger two from 8.9 to 9.6 to 1, and from 9.3 to 9.5 to 1 on the 50 ( the 60 was already at 9.5 to 1.)

Alternator output has gone up from 20 to 25 amps on the larger two engines, and is up to 17 from 10 amps on the smaller two.

There appear to be a number of small additional changes to help quiet the engines as well as accomodate and optimize the EFI, but details are a little sketchy at this time. The basic powerheads remain the same, except for the compression changes, as best I can tell. So does the 3-year warranty.

Most of all, I'm looking forward to the clean burning efficiency afforded by the EFI in a marine-specific designed engine.

The way I found this out was by investigating alternatives with dealers, and Gunther's C-Ddory dealership in Bodega Bay was able to make me a great deal on a new 2005 90EFI 4-Stroke.

Thanks to all the C-Brats and C-Dogs who have consulted with me privately and publicly in this search for a better re-powering option.

Thanks, guys!!!!! Joe.
 
Great news, Joe - looks like Honda is the last major player holding out on carbs. I'm sure that will change soon - hopefully they'll follow the lead of everyone else and provide some decent alternator output as well.

Guenters has always been real comptetitive on those Yamahas - good to hear they're treating you right. Are they doing the install as well?

What are you doing for gauges? Those Yamaha all-in-ones are pretty cool, but then you may end up with a couple extra holes in your dash from the old ones...

Dang - you may have to get a fuel flow meter... :lol:
 
The way I found this out was by investigating alternatives with dealers, and Gunther's C-Ddory dealership in Bodega Bay was able to make me a great deal on a new 2005 90EFI 4-Stroke.
Click to expand...

That answers my question on the "other" board. Since mine will need the 75 hp version in September, nice to know they're available. Though my dealer did comment that Yamaha engines are a bit backlogged.
 
Bill- Yep, Gunthers is doing the whole show, all new gauges, controls, prop, installation, sales tax (!%#$*$#*$!!!!), etc. They're even going to take in my old motor and kicker and sell them on the Internet for me for no charge, other than a servicing/tune-up.

I particularly liked the idea of having an experienced C-Dory dealer to the install. Also liked the strong Yamaha dealer network. I've dealt with Gunther before, a real Straight-Shooter and Honest Injun. Cuts to the chase and offers the bottom line up front.

Yep, it looks like Honda is going to have to play catch-up pretty fast. The Yamaha has a great dealer network as well. Great weight: 369 lbs. Looked a long time at the Suzi, but the weight (418 lbs) and thin network are limitations. The carbs vs. EFI was the big hang up for me that was solved by this new model. The big reason I had wanted a 115 Yammy EFI was for the EFI, not as an Aquatic Hot Rod. Dusty pointed out the insurability and liability issues, as did the dealers, who wouldn't install one on a 100 hp max CD 22. I have a new pontoon boat with EFI and wanted the same on the new motor. 33 hours running and never a misfire or stall. Hardly know its running. No more carbs or carb synchronization, either!

Those wanting to find out more can go to

http://www.yamaha-motor.com/products/su ... t=Midrange

and use the side bar to examine the features (the page above is the Specifications Page).

More, later. Joe.
 
flagold-

Here's how the 2004 alternator output's stacked up:

Mercury 90, 75 20, 20

Yamaha 90. 75 20, 20

Suzuki 90. 70 40, 25

Johnson 90, 70 40, 21.5

Honda 90, 75 16, 16


Average 90 27.5

Average 75/70 20.5


So I was glad to see the Yamaha go up from 20 to 25 for 2005. Depending on your ongoing electrical and battery charging needs, alternator output may be more or less important to you.

Solely for purposes of discussion, if you drew one 75 amp-hour battery down 50%, the 37.5 amp-hour deficit would take the following amount of times at the designated rates to recharge completely: (The max charge rate is achieved at approximately 3000 rpm and above.)

16 amp rate 2.43 hours or 146 minutes

20 amp rate 1.875 hrs 113 minutes

25 amp rate 1.5 hrs 90 minutes

40 amp rate 0.94 hrs 56 minutes

So those larger alternators start to look bigger and bigger and the smaller ones smaller and smaller.

If you don't have a lot of electrical accessories and never draw down your batteries hard (as in over night house uses), it might not make any difference at all how large your alternator is. But I kind of think having the extra capacity is like having reserve money in the bank when you need it.

If you notice the similarities between Yamaha and Mercury, and between Suzuki and Johnson, it's because Yamaha makes the powerheads for Mercury, and the Johnson is a Suzuki painted white.

Apparently the American manufacturers were unwilling or unable to invest in the R&D, the tooling, and the manufacturing facilities to produce 4-stroke powerheads. (Mercury dealers now claim Yamaha no longer makes their powerheads, but the specifications remain exactly parallel.)

Buy American!!! (?) Actually, if I had a Mercury (and I have a Mercury 4-stroke EFI), I'd be very happy to have a Yamaha powerhead on it!

HTH. Joe
 
Thanks Joe, that was a good explanation. I have that Mercury 90 and have been very pleased with it.

On the alternators -- I had assumed the alternator sent current to the onboard charger and the charger then charged the battery at whatever it is set to. Is that incorrect? I hope it is, since those charger units are usually set low and if the engine is charging direct -- that would be best.

Thanks again!
Matt Mattson
 
flagold- If by "on board chargers" you mean the ones that charge your batteries when you're on shore (110v) power, then the answer is this:

The alternators always, as far as I know, directly charge the battery(ies) they are directly connected to or through the 2-All-1-off switch, if so equipped.

The on-board charger only operates when the shore power is on, otherwise it's isolated with diodes (one way solid state components) from the batteries.

The alternator outputs direct current (no polarity alternation) in the 12-15 volt range and directly pushes charge back into the batteries.

The on-board charger operates off 110 volt AC (Alternating current), which must be reduced in voltage and rectified (changed into DC). For this, it uses a transformer and diodes. Electronic switching circuitry regulates and tapers the charge, depending on the design of the charger.

Hope this helps! Joe.
 
Joe,

I was very pleased to hear this good news. I had given up on Yamaha to make a EFI 90 fourstroke available. Next time you're in contact with Guenters, I presently have a low time 1991 Yamaha 90 2-stroke & a 9.9 4-stroke High Thrust.

That's Great news,

Bill
 
Bill-

My guess is that, given time for every manufacturer to get their conversions made, probably almost all outboards from at least 50 hp up will have fuel injection, except those models headed for parts of the world where fuel quality cannot be guaranteed and the traditional carburetor becomes more practical.

You have a private message, also. Joe.
 
If I'm not mistaken, Les mentioned EFI was inevitable for all the manufacturers due to upcoming emissions requirements. There's just no way they can make the carb motors much cleaner...
 
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